Semi-targeted Lipidomics of Plant Acyl Lipids Using UPLC-HR-MS in Combination with a Data-Independent Acquisition Mode.

In recent years, multiple mass-spectrometric methods have been developed to tackle fundamental analytical questions in the field of biology and biochemistry. One essential approach relies on the use of liquid chromatography (LC), for efficient compound separation, coupled to high-resolution mass spectrometry (HR-MS). Even though these techniques are highly sensitive allowing for the reliable measurement of several thousand mass features, the major bottleneck is to convert the measured masses into annotated lipid species. To overcome this problem, we present a simple, example-based workflow, which provides an introduction to basic strategies for the manual validation of LC-MS-based lipidomic data. The whole strategy makes use of a data-independent acquisition (DIA) method, where alternating MS measurement cycles using high and low-energy scans are used. This measurement strategy allows to reliably annotate lipids, based on the exact mass measurements of intact, but also fragmented lipids from continuously recorded spectra.